Alloy



Patented Dec. 20, 1932" A UNITED "STATES PATENT OFFICE WILLIAM H.BASSETT, J'B., OF SCARSDALE, AND ROBERT E. LEACH, OI FAIBFIELD,CONNECTICUT, ASSIGNORS TO'ANACONDA. WIRE & CABLE COMPANY,

OF NEW YORK, N. Y., A. CORPORATION OF DELAWARE v ALLOY No Drawing.

Our invention relates to a metal alloy composed principally of copperand particularly 7 suitable for making conductor wires such as tivelyhigh tensile strength without sacrificing conductivity to too great anextent. For example, a certain size of bronze trolley wire having atensile strength of 61,000 pounds per square inch and a conductivity ofnot less than 90% of the conductivity of a copper wire of the samediameter. Other types of wires 'may require a tensile strength evenhigher than 61,000 pounds per square inch, the requirements for lead-inwires of certain types being about 90,000 pounds per square inch.

Heretofore copper-cadmium alloys have been employed in order to obtainthe desired tensile strength and conductivity, the cadmium constitutedbelow approximately 1% of the alloy. The cadmium increases the tensilestrength of the alloy but tends to decrease its conductivity. contentreaches 0.75% of the alloy or 1%, the alloy becomes extremely difiicultto roll in the usual commercial hot rod mill because alloys containingthese, or larger quantities of cadmium, can'be successfully handled onlywithin a narrow temperature limit. Therefore, the metal tends to crackwhen subjected to the usual hot rolling treatment. This is particularlythe case in alloys made with tough pitch copper at copper refineries. 35An object of our invention is to produce an alloy consisting principallyof copper and containing cadmium which will readily per mit thecommercial hot rollin or cold rolling of the alloy into bars and therawing of these bars to the required dimensions; and to provide an alloyhaving a high tensile strength, ductility and electrical conductivity.

Another object of our invention is to pro vide a method of making alloyof the above type and for forming it lnto wires or cables.

11 our invention we form an alloy of copper, cadmium and silver, thesilver replacing a proportionate part of the cadmium in a copper-cadmiumalloy. By thus substituting silver for some of the cadmium in the alloyApplication filed February 20, 1981. Serial No. 517,801.

When the cadmiumit is possible to obtain equal or better physicalproperties. 'For example, an equal tensile strength may be'obtained witha higher conductivity or, for a wire of the same conductivity, a highertensile strength may be obtained.

Moreover, the alloy can be easily handled in hot rolling operatlons,even with a hi her content of cadmium and silver inasmuc as the rollingtemperature need not be in as narrow a range as in the case of acopper-cadmium alloy of the same total alloying constitiuents.

The proportions of the silver and cadmium in the nal alloy are but afraction of a per cent of the alloy, the cadmium content ranging fromabout 4% to about 1% and the silver from about to about the balancebeing copper. For exam 1e, an alloy containing silver, A7?) ca mium and7 the balance copper, has a conductivity of approximately based on theinternational annealed co per standard at 20 C. and has the requirestrength, meeting the. breaking strength requirement of pounds for 0.051.7 inch diameter hard drawn wire and 1600 pounds breaking strength for0.162 inch diameter, hard drawn wire. The conductivity of the wire andthe, exact strength following adefinite amount of cold working dependsupon the cadmium and silver'content of the alloy, the materialcontaining the smaller amount of cadmiumand the smaller amount of silverhaving a higher conductivity and a lower strength than the materialhaving a larger content of cadmium and c of silver.

The alloy may be formed by introducing the cadmium and silver indetermined quantities directly into the copper or by preparing an alloyof cadmium and silver in the required proportions and amounts and thenintroducing this alloy into the copper. The

latter method is preferred as it is easier to obtain a better control ofthe composition of the alloy.

In manufacturing this alloy into a wire the material is preferably castinto 200 pound bars of approximately four inches s uare in cross sectionor into 250 pound bi lets of approximately five inches diameter. Thebars or billets after casting are heated in a. mufile furnace and hotrolled to the final rolled diameter ranging from ths of an inch to thsof an inch, depending upon the type of material to be drawn. The wireafter being drawn to size may be wound on a reel. It may then be passedthrough a flux and through molten tin and wiped to give a satisfactorytinned surface in order to protect the wire from rubber or insulatingmaterials in the event that the wire is to be insulated. Wires of thistype are suitable for use as trolley wires, telephone and telegraphdistribution wires, twisted pair drop or leadin wires such as are usedfor telephone installations, and for alloy or composite cables, whetherused for stranded conductors or cables of hollow conductor type, and forother numerous purposes.

Our alloy gives a. wire which is especially adapted to commercialproduction in copper refineries or tough pitch copper whether or notdeoxidized with a metallic reducing agent. It can be subsequently hotrolled and drawn in accordance with standard commercial processes intovarious sizes and shapes of wire. In addition to its high strength andhigh electrical conductivity, it has a high resistance to abrasion anderosion.

What we claim is:

1. An alloy consisting of copper, cadmium and silver, the cadmiumcontent being between approximately one quarter of a er cent and 1%, andthe silver content being between approximately one-eighth of a per centand tliree quarters ofa per cent.

2. A process of making an alloy of the above type which comprisesforming an alloy of cadmium and silver and adding said alloy to copperin amounts less than 2% of said copper. i

3. The process of claim 2 in which the cadmium and silver contents ofsaid alloys are between one-quarter and 1% and oneeighth andthree-quarters of a percent respectively of the total amount of theresulting alloy.

In testimony whereof, we have hereunto signed our names.

\VILLIAM H. BASSETT, JR. ROBERT H. LEACH.

